This invention relates to a procedure as specified in claim 1.
In many cases, hearing impairment affects both ears so that both should be fitted with a hearing aid. So-called stereophonic or binaural hearing aids have been used in the past. More modern hearing-aid designs, typically equipped with at least two microphones, incorporate between these microphones and their output converter assembly, operating with an electromechanical converter, transmitter units in which the audio signal is processed and which can be operated in different, switchable transmission modes. For example, the audio-signal processing in one mode may be so tailored as to produce a relatively focussed audio-signal reception pattern while in the second mode a relatively nondirectional reception pattern is obtained, a third mode serves to squelch loud acoustic background noise, a fourth mode is particularly suitable for concert-hall use, etc. The switching from one transmission mode to another is done on the hearing aid itself, for instance by means of a toggle switch, with the user often being confused as to which of his two hearing aids is currently operating in which mode. One must consider that differentiating between the individual transmission modes in each of the two hearing aids is very difficult.
To solve this problem, a more recent approach in some cases has been to design remote control devices capable of controlling two hearing aids. To be sure, carrying and operating a remote control unit is not cherished by all users. A remote control, however, makes it possible to synchronize the transmission modes of both target hearing aids, for instance by only once pressing a single button that controls both hearing aids.
There also exist modern hearing aids which analyze the acoustic environment and on the basis of that analysis of the environment automatically make adjustments to obtain the optimal transmission mode. Where these devices are used binaurally, the mode adjustment for both hearing aids is often asynchronous since both units receive different audio patterns due for instance to head interference. Considering how quickly the acoustic environment and the head position can change, this may be irritating to the user.
This invention is aimed at introducing a procedure of the type first mentioned, as well as a hearing-aid set with appropriate individual hearing aids, by means of which the aforementioned problems including especially the need for a remote control are eliminated while permitting the easy, automatic control of the transmission mode selection for binaural hearing aids. This is accomplished by employing the above-mentioned procedure with the characteristic features per claim 1.
By manually or automatically synchronizing the respectively enabled transmission modes of the hearing aids via a wireless connection between themxe2x80x94preferably a high-frequency connectionxe2x80x94so as to be matched at a setpoint or selectable level, such synchronization can be obtained without a remote control unit for instance by pressing a button on one of the hearing aids or, along preset criteria described further below, by an automatic feature acting on both hearing aids, or by means of an added remote-control option.
In a first preferred implementation, the synchronization is established in a way that the two hearing aids, once synchronized, operate in the same active transmission modes. This can be accomplished by making one of the hearing aids the slave unit which adopts the respective mode of the other unit, the master. Which of the two hearing aids is the master can be predetermined, for instance the right-ear unit, but a situation-related changeover is possible for instance by selecting certain transmission modes as dominant modes which in the synchronization process determine the transmission mode of the other unit. For example, in automatic mode-enabling operation one of the hearing aids may be in a relatively infrequently used mode, such as the concert-hall setting, while the other unit may be operating in a standard mode. In that case, the synchronization will cause the hearing aid in the less frequently used transmission mode to connect to the hearing aid in the currently active standard mode and to adopt the latter.
It is also entirely possible in the case of hearing aids operating in different modes prior to synchronization to have such synchronization cause a switch to neither of these modes but to a third, common mode. This can be desirable when both hearing aids were in an infrequently used transmission mode, one for instance at the concert-hall level, the other at the loud-noise-squelching level. Upon synchronization, both hearing aids could thus be reactivated in the standard mode.
In another implementation of the procedure according to this invention, combinable in certain cases with the first procedure, synchronization causes each of the transmission modes to be switched to a different mode. This would be desirable in view of the ACTUAL pre-synchronization mode constellation which, empirically, is not made uniform but optimized. For example, if the pre-synchronization mode constellation involves two opposite modes, one being for instance at the concert-hall and the other at the loud-noise-squelching level, the synchronization could be so chosen as to adjust one unit for instance to the xe2x80x9cslightly noisy environmentxe2x80x9d mode, the other to the standard mode, a post-synchronization constellation which, as experience has shown, will in most cases be a more satisfactory adjustment from the prior setting.
It is also entirely possible, in addition or as an alternative, to select the transmission modes enabled by synchronization based on an analysis of the currently prevailing or developing acoustic environment, in a way that for instance in the event of a strong change in the acoustic environment a synchronization process is triggered and the transmission modes are suitably adjusted. It is easy enough, for example in the case of a strongly increasing noise level which is registered primarily in one hearing aid, to enable an xe2x80x9cincreased attenuationxe2x80x9d transmission mode in both hearing aids even though the second unit may not as yet have registered the augmented level due for instance to temporary head interference.
The synchronization itself can be triggered either manually on one of the hearing aids, or via remote control and/or through the result of an analysis of the current acoustic environment and/or through specific mode constellations which at least over an extended period have not been empirically determined as being optimized.
By virtue of the fact that there is a wireless communication link between the two hearing aids whereby merely a control signal for the selection unit is sent from one hearing aid to the other, it is possible to establish a binaural balance between the hearing aids without the need to transmit complex audio processing signals between the hearing aids with a substantial attendant increase in energy consumption. For the synchronization as intended by this invention it suffices to transmit a few bits, identifying the desired transmission mode, with a long repetition rate from a few seconds to several minutes, which puts virtually no load on the power consumption. Moreover, it follows a short, mechanically most stable transfer path between the ears of the user, which also provides high immunity to RF interference.
The following describes this invention by way of examples with the aid of drawings in which: